Thanks for the info matey.
The problem i have had the last 2 times is i was using tyres that have gone off, hence me wanting better tyres, but as some of the guys have said its no point in getting the tyres if they are going to cause it to bog.
Ideally i need to find someone who has used drag tyres on an NA before i go down that route.
Mph on the runs has been fine, usually a good few mph above the other NAs but i have one of the worst 60fts at 2.35, i literally either bogged or span the tyres, anymore than 3500rpm and it span, any less and it bogged.